Specification :

disc harrow is a farm implement that is used to cultivate the
soil where crops are to be planted. It is also used to chop up
unwanted weeds or crop remainders. It consists of many iron
or steel discs which have slight concavity and are arranged into
two or four sections. When viewed from above, the four sections
would appear to form an " X" which has been flattened to be
wider than it is tall. The discs are also offset so that they are
not parallel with the overall direction of the implement. This
is so they slice the ground they cut over a little bit to optimize
the result. The concavity of the discs as well as their being
offset causes them to loosen and pickup the soil they cut.